48"slide-out

First off; after the Dam Gathering; I've put the Palace on the back burner and pulling out the plans for The Zephyr.
I plan on using the forward, slide-out galley. Tried finding 48" slide units but don't want to lay down that kinda $$. So to anyone who has built a slide out, how did you construct the slide?
I plan on using the forward, slide-out galley. Tried finding 48" slide units but don't want to lay down that kinda $$. So to anyone who has built a slide out, how did you construct the slide?